A magnetic topological semimetal Sr1−yMn1−zSb2 (y, z < 0.1)

• Published in: Nature materials 2017-09, Vol.16 (9), p.905-910
• Main Authors: Liu, J. Y., Hu, J., Zhang, Q., Graf, D., Cao, H. B., Radmanesh, S. M. A., Adams, D. J., Zhu, Y. L., Cheng, G. F., Liu, X., Phelan, W. A., Wei, J., Jaime, M., Balakirev, F., Tennant, D. A., DiTusa, J. F., Chiorescu, I., Spinu, L., Mao, Z. Q.
• Format: Article
• Language: English
• Subjects: 639/301/119/995; 639/766/119/997; Antiferromagnetism; Biomaterials; Breaking; Condensed Matter Physics; Crystals; Electron mass; Fermions; Ferromagnetic materials; High Magnetic Field Science; Magnetic fields; MATERIALS SCIENCE; Metalloids; Metals; Nanotechnology; Optical and Electronic Materials; Photonic crystals; Relativism; Symmetry; Topology
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat4953

Weyl (WSMs) evolve from Dirac semimetals in the presence of broken time-reversal symmetry (TRS) or space-inversion symmetry. The WSM phases in TaAs-class materials and photonic crystals are due to the loss of space-inversion symmetry. For TRS-breaking WSMs, despite numerous theoretical and experimental efforts, few examples have been reported. In this Article, we report a new type of magnetic semimetal Sr 1− y Mn 1− z Sb 2 ( y , z < 0.1) with nearly massless relativistic fermion behaviour ( m ∗ = 0.04 − 0.05 m 0 , where m 0 is the free-electron mass). This material exhibits a ferromagnetic order for 304 K < T < 565 K, but a canted antiferromagnetic order with a ferromagnetic component for T < 304 K. The combination of relativistic fermion behaviour and ferromagnetism in Sr 1− y Mn 1− z Sb 2 offers a rare opportunity to investigate the interplay between relativistic fermions and spontaneous TRS breaking. Sr 1− y Mn 1− z Sb 2 ( y , z < 0.1) is reported to be a magnetic topological semimetal exhibiting nearly massless relativistic fermions.